Tuesday, 22 April 2014

The Hourglass Sea

As the red planet reached opposition earlier this month, shining brightly over my garage roof, I thought I would do a post on significant moments in our relationship with our celestial neighbour.

The red planet

The ancient Greeks looked up and puzzled at the peculiar behaviour of Mars during its periods of apparent retrograde motion as the Earth, supposedly the fixed centre of their universe, passed it on the inside, making it appear from Earth as though Mars was moving in the opposite direction. Hipparchus of Nicaea, who compiled the earliest known catalogue of the stars in the 3rd Century BC, set out to explain this phenomenon through the theory of epicycles. These were small circular orbits traced out by the planets as they moved in larger circular orbits; known as deferents, around the Earth. Along with the misguided concept of an Earth-centric universe, the idea that the universe must possess a perfect nature and that the orbits of the planets must therefore be perfectly circular, caused the ancients to overcomplicate their explanation for the motion of the planets.

The great Alexandrian scholar Claudius Ptolemy, (90-168AD) whose vision of the cosmos would dominate for over a millennium, added further layers of complexity in his efforts to make the erratic motions of the planets fit within the framework of a perfect universe; centring their orbits around an imaginary central point known as the equant. With hindsight, it was all a case of trying to make the facts fit the theory, but until Nicolaus Copernicus looked up and pondered the heavens anew, no-one had a better idea.

 Copernicus' assertion in his seminal work of 1543, De revolutionibus orbium coelestium, published shortly before his death, that the sun and not the earth was the central point about which the planets moved, was not universally accepted. One man who had trouble letting go of the idea of an earth-centric cosmos was the larger than life and magnificently moustached  Danish scholar Tycho Brahe, (pictured right).
Brahe was not a man to let go of an argument easily. The gold prosthetic that covered his nose was testament to that. He had lost part of his nose in a duel over a mathematical dispute. So the story goes. I bet there was a woman involved somewhere.

Brahe fell out with the king of Denmark too and left in 1597 to serve as court astronomer to Emperor Rudolph II in Prague. Tycho had his own ideas about the universe. Through his observations of a supernova he had shown the cosmos to be dynamic and evolving, dispelling classical notions of unchanging perfection. Nevertheless he clung to the idea of a universe with the earth at its centre but came up with a new model in which the sun circled the earth but the other planets circled the sun. Brahe amassed copious amounts of data from detailed observations of the heavens in the hope of lending empirical weight to his theory. In 1600 Brahe was joined by the young Johannes Kepler, fleeing religious persecution in Graz. Brahe put Kepler to work studying his observations of Mars with the object of elucidating its orbit. After five years of work, in which he proved that Tycho's observations could not be fitted to a circular orbit, Kepler would publish his seminal Astronomia Nova, in which he announced that the orbit of Mars was elliptical, as must be the orbits of all planets; a conclusion enshrined as his first law of Planetary Motion. The solution was simple in its elegance and the Ptolomaic universe of equants and epicycles was consigned to the dustbin of history, where it would soon be joined by the Tychian model, though mercifully Brahe did not live to see this. Doubtless he would not have taken it well.

The apparent orbit of Mars as drawn by Cassini

As the telescope age dawned, further details of the nature of Mars were revealed. The first to observe the Martian polar ice caps was Christiaan Huygens who produced a sketch of the planet in 1659, showing three distinct views featuring different surface features. Between 1704 and 1720 Giacomo Maraldi, nephew of Gian Domenico Cassini, was following in his uncle's footsteps at the Paris observatory when he decided to take a particular interest in Mars. Maraldi too observed the polar caps and noted that they grew and shrank at different times. He was also able to observe other surface features on the planet, describing the shadowy band made by larval seas, although he believed the shadow to be a result of clouds in the Martian atmosphere rather than any solid entity. Through observation of the feature now known as Syrtis Major, 'the Hourglass Sea', Maraldi was able to determine Mars' rotation period at 24 hours and 40 minutes.

The advent of the 'Newtonian' reflector telescope brought better views of Mars than ever before. In the early 1780's William Herschel turned his attention to Mars with a 20 foot long reflector and observed with interest the changing nature of the poles. Herschel proposed that the growth and shrinkage of the polar caps was seasonal. He also demonstrated that Mars had very little atmosphere by observing that there was no discernible dimming of stars immediately before they passed into the shadow of the red planet. It was in the course of such observations in 1881 that Herschel made his most famous discovery; the planet Uranus. The moment of discovery is immortalised in this contemporary engraving (left) showing William and Caroline Herschel at work.

By 1862 the largest telescope in the world was the 26 inch reflector at the US Naval Observatory in Washington DC. Here the resident professor of astronomy was Asaph Hall, who sometimes received visits from Abraham Lincoln, who was fascinated by the work at the observatory. Hall enjoyed a prodigious career, publishing 500 papers on matters astronomical and determining the rotational period of Saturn. Hall's greatest quest was his search for satellites orbiting Mars. Finally he despaired and was ready to abandon the search but was encouraged to continue by his wife. And so he pressed his eye to the telescope once more and in 1877, within the space of a week after years of searching, he identified not one but two moons circling Mars. He named them Deimos and Phobos after the sons of Mars. Both moons are tiny, at just 14 and 8 miles across and are believed to be captured asteroids.

Drawings of Martian canals by Percival Lowell
It was a splendid achievement but would be overshadowed, in the public imagination at least, by the announcement in the same year by Milanese astronomer Giovanni Schiaparelli that he had observed 'canals' on Mars. Schiaparelli was an accomplished astronomer and had published his observations using the term 'canali' literally 'channels' to describe the features that he was seeing. These are now known to have been an optical illusion caused by the chance alignment of craters when viewing the Martian surface at the limit of resolution of Schiaparelli's telescope. Enter wealthy businessman and astronomy enthusiast Percival Lowell. Seizing upon the mistranslation of Schiaparelli's 'canals' Lowell embarked upon an obsession with the non-existent features, building a state of the art observatory in Arizona to aid his quest to explain the mystery of these Martian canals, suggesting that they had been created by intelligent beings living on Mars. The observatory that Lowell founded was nevertheless a great legacy and it was here in 1930 that Pluto was discovered. The proof of the existence of an outer planet had become Lowell's new quest although he did not live to see the vindication of his theory.

The idea of Martians was firmly embedded in the public consciousness and in 1898 HG Wells' classic War of the Worlds was published, inspired in part by Lowell's ideas. Illustration right is from a 1908 edition. Legend has grown up around the mass panic that was suddenly sparked by Orson Welles' radio dramatization of War of the Worlds for the Mercury Theatre on Air in 1938.  The story goes that Welles began his broadcast with an explanation that it was a fictional dramatization but that most people were listening to the popular Edgar Bergen show on another station. When Edgar's show finished, people belatedly tuned in to Orson Welles' ultra realistic news bulletin style War of the Worlds and wrongly assumed that it was all really happening, with mass hysteria resulting. Sadly it seems that this is a myth and that stories of the panic were wildly exaggerated by the American press, with the newspapers taking the opportunity to show the arriviste wirelessmen in a bad light as reckless purveyors of misinformation. They of all people should have known however that there is no such thing as bad publicity. After all, has anyone these days heard of Edgar Bergen?

Man has yet to set foot on Mars but has done the next best thing by landing probes and rovers on the surface. The United States has led the way with its Mariner and Viking  missions of the 1960's and 70's and the redoubtable Curiosity and Opportunity rovers that have brought us such wonderful images in recent years. Appropriately enough however, it was the Soviet Union that first landed a craft on the surface of the red planet, albeit not very successfully.

Soviet efforts to reach Mars began in 1962, just as the US Mariner programme was also beginning. The Soviets launched four missions to Mars, only the last of which made it out of Earth orbit and out into interplanetary space for a distance of over one hundred million kilometres from earth before losing its way. Two more efforts to launch an orbiter in 1969 both exploded shortly after launch.

Efforts were nevertheless stepped up and continued with the ambitious launch in 1971 of Mars 2 & 3 which were combined orbiter/lander craft. Both craft successfully reached Mars and went into orbit around the red planet in the summer of 1972. The US Mariner 9 had already become the first craft to successfully make it into orbit around Mars the previous year. Now however the Soviets had the opportunity to move ahead of their rivals. The landers were released into the teeth of a fearsome Martian dust storm and the Mars 2 lander crashed on the surface. Mars 3 made a successful landing on the surface but may have sustained some damage. It reportedly sent a 20 second transmission including one grainy image before communications were lost, though some have questioned whether the transmission occurred. The orbiters continued their mission, sending back images and details of the atmospheric temperatures, pressures and chemical composition.

Follow up missions launched in 1973 were largely disappointing. The Mars 4 mission failed to enter Mars orbit and flew right by the red planet. Its twin Mars 5 was more successful and orbited the planet, gathering images and more details of the atmosphere, surface temperature and composition and magnetic field. Two more missions were launched with the intention of landing more modules on the surface. Mars 6 released its lander successfully but a likely failure of the landing retro boosters caused it to slam into the surface. Mars 7 was an identical mission but a fault caused the landing module to be released too soon and it missed the planet altogether. The inability of the Soviets to prevent the degradation of their computer chips during the flight to Mars has been blamed for the majority of the failures. In 1975 the successful US Viking missions were launched and both subsequently made successful landings on the surface and sent back sustained transmissions, effectively ending the Cold War race to explore Mars.

In a post script NASA's Mars orbiter last year took a picture of what is believed to be the Soviet Mars 3 lander, sitting on the Martian surface in the Ptolomais crater, providing potential proof that the Soviets did indeed make it to the red planet first.

The Cold War propaganda poster is not especially related to the Mars programme but I liked it.

Read more space related posts on Slings and Arrows

Kepler and Mars
Maraldi and Herschel

Asaph Hall and the moons of Mars

Canals on Mars

War of the Worlds Mass Panic

The Soviet Mars Programme

Mars 3 Found?

Friday, 4 April 2014

Rise of the Rus

Having visited the excellent Viking exhibition at the British Museum last week, I thought I would write a post on the Rus, whose activities received an overdue focus in the exhibition which featured many artefacts from their stomping grounds. As the opening quote shows, they are a familiar lot.
The Rus on the rampage

There was an invasion of the barbarian Rus, a people, as everyone knows who are brutal and crude and bear no remnant of love for humankind. They have savage customs and are inhuman in their deeds, displaying bloodthirstiness in their very appearance. They rejoice in slaughter more than in any other thing that people naturally enjoy. This nation, destructive both in deed and name, began their brutal outrage from the Propontis and then spread up the coast. They came as far as the native city of the saint and cut down unsparingly people of both sexes and every generation. They did not pity the old or overlook the young but rather raised their bloodthirsty hands equally against all and hastened to bring destruction with as much force as possible.

So says the Life of St George of Amastris (pictured below) in recording what could be the earliest reference to a raid by the Rus upon the territory of Byzantium early in the Ninth Century AD. Its author gave these Vikings who had made their way down the River Dnieper into the Black Sea to raid the communities on its shores, about as good a write up as they received from the monkish chroniclers who had recorded the 793 raid on Lindesfarne  in very similar language. Amastris, we are told, was saved by a miracle, for when the raiders tried to break into the saint’s tomb, they were struck down by the power of God and became weak and helpless.

Whilst there is considerable debate about the date of this raid on the Paphlagonian town of Amastris, it is clear that by the early Ninth Century, the people known as the Rus were viewed as a significant threat. Early in his reign emperor Theophilus took considerable steps to protect the empire’s trading interests on the northern shore of the Black Sea. Ongoing hostilities between the Byzantines and the Caliphate would ensure that the route by which luxury goods reached Constantinople from the east would shift increasingly to the Caspian Sea and thence via the great rivers of the Volga and the Don to the Black Sea. Trade with the peoples to the north would therefore grow in importance. The major power in the region between the lower reaches of the Dnieper and the Volga were the Khazars; a Turkic people who had been on good terms with the Byzantines for two centuries whilst staving off attempts at conquest from the Arabs. The Khazar Khagan had astutely adopted Judaism as his religion in order to resist efforts from both empires to convert his people and thereby place him in a position of being seen as antagonistic to one or the other. The Khazar capital of Itil at the mouth of the Volga was a trading enclave from which ships set out across the Caspian Sea to trade furs, slaves, amber, honey and wax with Abbasid merchants and return with silks and spices from as far afield as India and China as well as Persian glassware and pocketfuls of jingling silver dirhams. Heading northwards from Itil, boats could make their way up the Volga and then turn westwards, making use of smaller waterways and where necessary portage to enter the Don and then turn south for the Black Sea and the ports of the Byzantine Empire.
It was to protect this trade that Theophilus took action in 833, establishing a new province in the Crimea known as the Klimata which incorporated the previously independent city of Cherson at the mouth of the Dnieper under direct Byzantine control. A permanent force of 2000 troops was dispatched to the new province under the command of a military governor. At the same time Theophilus sent a task force of engineers and soldiers under the governor of Paphlagonia to build a new fortification close to the mouth of the Don. Known as Sarkel, the white house, this construction served to protect the Khazar controlled town of Tamatarkha which was dominated by a Jewish merchant community. It is believed that Sarkel anchored the western flank of a line of earthworks and fortifications stretching between the Volga and the Don. The scale of this undertaking clearly demonstrates the level of threat that faced by the region from the potentially aggressive newcomers to the north. The most potent threat was believed to be posed by the Rus.

Itil was home to communities of merchants including a sizable contingent of Rus, who represented the southern terminus of a commercial network stretching all the way back to Scandinavia. Approximately 200,000 silver coins have been found throughout Scandinavia dating from the Viking period. Of these around half were turned up on the island of Gotland and 40,000 of these were Abbasid dirhams. It is an eloquent illustration of the extent and importance of the trade links established by the intrepid Rus.
Rus traders resorting to portage - Olaus Magnus
The first permanent Viking presence in what is now Russia was established in the form of fortified settlements along the shores of Lake Ladoga during the mid Eighth Century. Setting out from their Swedish homeland, the first colonists came both as warriors and as traders, as the presence of both a sword and a set of scales as grave goods for the same individual testifies. They had the capacity to fight for land or plunder and to defend and keep it and to take slaves in large numbers from the native population to be sold down the river. They could however, also offer protection to the native population and they set out to put down roots and establish peaceful and profitable trade. Indeed, so welcome did the Viking presence become that in the end a legend was born that the natives, tired by ceaseless infighting, had actually invited them to come and rule over them. Such is the tale of Rurik, eldest of three Viking brothers who is credited with establishing his rule in the town of Gorodisce, known as Holmgard in the Icelandic sagas, on Lake Ilmen, near the headwaters of the Volga.
The furry critters of Russia never stood a chance - Olaus Magnus
The Primary Russian Chronicle, which was written in Kiev around 1100, dates the beginning of Rurik’s kingship to 860, but we know there was a significant political entity controlled by a Rus ‘Khagan’ established well before this date. In 838 a Rus delegation arrived in Constantinople, having made their way down the Dnieper. It has been posited that these Rus ambassadors came to seek improved trading relations with the empire following the Amastris raid. What was discussed with Theophilus is not recorded and we know of their visit from a Frankish source, the Annals of St Bertin, which records the arrival of these envoys at the court of Louis the Pious in 839 accompanying a Byzantine embassy. The Rus declared that the reason for their diversion west was that they feared ascending the Dnieper on account of the hostile natives. At this stage therefore the Rus clearly had not achieved control over the Dnieper route. Louis, who trusted Vikings not a jot, detained the envoys as spies.

The Russian Primary Chronicle credits two brothers, followers of Rurik, with the initial, seemingly peaceful conquest of the town of Kiev on the Dnieper. They are named as Askold and Dir. Having found the town conveniently leaderless due to the deaths of its previous rulers they set about restoring good governance. The situation sounds too good to be true but however it was achieved, it seems that the Rus gained a crucial strategic foothold on the Dnieper in the mid 9th Century, wresting control of Kiev from the Khazars. It was from Kiev, so the chronicle informs us, under the command of these two enterprising Vikings that the terrifying raid of 860 on Constantinople took place.

Photius dips the robe in the sea
Theophilus’ successor Michael III was away on campaign against the Abbasids and the imperial fleet was also absent from the capital when on the northern horizon there appeared a great host of sails and soon the terrorised citizens beheld the awful spectacle of a two hundred strong fleet of longships descending upon them. Swarming into the Bosphorus ‘like wasps’ as the Patriarch Photius described them, these invaders fell upon the vulnerable monasteries along the shore and on the islands in the Marmara. The Rus burned and pillaged as they saw fit; destroying everything outside of the protective walls of the capital quite unopposed. The city itself remained invulnerable however and so once all  of the easy pickings had been taken the Rus turned for home. A later legend grew up around the raid, which is preserved in the Russian Primary Chronicle, in which the Patriarch Photius dipped the sacred relic of the robe of the Virgin Mary into the waters of the Golden Horn. All at once a storm blew up and scattered the ships.

Control of Kiev was consolidated by Oleg, who we are told succeeded Rurik as regent for his young son Prince Igor. Oleg moved his capital to Kiev in 880 and the kingdom of Kiev Rus would grow to eclipse the Khazars as the pre-eminent power of the region. Trade was the name of the game but the Rus were prepared to fight for their rights. In 907 Oleg led another fleet against Constantinople. The details of the attack in the Primary Russian Chronicle are irresistible if somewhat fanciful.

Oleg disembarked upon the shore, and ordered his soldiery to beach the ships. They waged war around the city, and accomplished much slaughter of the Greeks. They also destroyed many palaces and burned the churches. Of the prisoners they captured, some they beheaded, some they tortured, some they shot, and still others they cast into the sea. The Russians inflicted many other woes upon the Greeks after the usual manner of soldiers. Oleg commanded his warriors to make wheels, which they attached to the ships, and when the wind was favourable they spread the sails and bore down upon the city from the open country. When the Greeks beheld this, they were afraid, and sending messengers to Oleg, they implored him not to destroy the city, and offered to submit to such tribute as he should desire.

Oleg's shield is nailed to the walls of Constantinople

The Byzantine sources are silent on this raid although we know that Leo VI concluded a treaty with the Rus in 911. According to the RPC, under the terms Oleg agreed, Russian merchants were to be permitted to enter the city in groups of fifty and were able to stay for up to six months to trade. They were to be provided board and lodging and hot baths on demand and were able to purchase goods for their needs tax free. The Byzantine sources beg to differ and it may have been another half century before this package of trading rights was on the table after the Rus had resorted to the brutally persuasive tactic of armed raids on a few more occasions, each time negotiating a better deal in exchange for withdrawal.

In 913 similar tactics were adopted against the Caliphate. The Arab writer al-Mas'udi tells us that they entered the Don from the Black Sea with 500 ships and then made their way via the Volga to Itil and thence into the Caspian, terrorising the communities on its shores. His account once again echoes those of Anglo Saxons, Franks and Byzantines who encountered Vikings on the rampage.

The Rus spilled rivers of blood, seized women and children and property, raided and everywhere destroyed and burned. The people who lived on these shores were in turmoil, for they had never been attacked by an enemy from the sea, and their shores had only been visited by the ships of merchants and fishermen.

According to Mas'udi the Rus occupied islands in the Caspian from which they repelled an attack by the Arab forces, but when they returned upriver they were set upon by the Muslim subjects of the Khazars and put to slaughter. It would be thirty years before they attempted another expedition of this type and they settled down to peaceful trade once more.

So this was how it was to be. The Rus would be good neighbours but only on the terms that suited them, and those would be negotiated at sword point if necessary. Well what did the Arabs and Byzantines expect? The Rus were Vikings after all.

Vikings at the British Museum

Excellent article on the archaeological evidence for the early Rus

The Life of St George of Amastris

The Russian Primary Chronicle